The following are copending applications and are hereby incorporated by reference: U.S. patent application Ser. Nos. 10/080,197, 10/080,180, 10/080,192 , now U.S. Pat. No. 6,597,305 ; and U.S. patent application Ser. No. 10/079,477, all filed on Feb. 19, 2002.
Weather radar is a substantial aid for detecting adverse weather conditions that are hazardous to flying aircraft such as clear air turbulence, windshears, microbursts, and aircraft generated wake vortices. Pilots have exploited such radars to avoid these weather conditions, and due to the radars"" capability of early detection, have done so with minimal impact upon the total flight time and distance.
In spite of the detailed information the radar returns present, it is still difficult to distinguish between terrain and hazardous weather. There are many types of surfaces that will produce nearly identical, and thus indistinguishable, radar returns. Wherever the terrain intrudes into the illuminated view of the weather radar, it, too, will return a radar signal. To the pilot, such returns might present themselves as weather or might act to confuse the display in a manner such that the ground clutter obscures a weather system that would present a danger to flight. Removing the xe2x80x9cground clutterxe2x80x9d will allow the pilot to reliably discern the weather information contained within the radar returns.
Therefore, a method to suppress radar returns from terrain in weather radar would be useful.
The present invention comprises a system, method, and computer program product for generating various weather radar images allowing the suppression of terrain-based radar returns. A weather radar display system includes a memory, a terrain database, a display, and a display processor coupled to the memory, terrain database, and the display. The display processor includes: a first component configured to extract radar return data stored in the memory based on aircraft position; a second component configured to extract data stored in the terrain database based on aircraft position; and a third component configured to selectively accept or suppress data for display based upon the data extracted from memory and the data extracted from the terrain database. The resulting weather radar display portrays only the weather within the relevant airspace, the lower limit of which is defined by the known terrain features.
In accordance with further aspects of the invention, the first component extracts the radar return data from a three-dimensional buffer.
In accordance with other aspects of the invention, the three-dimensional buffer is also circular.
In accordance with still further aspects of the invention, the three-dimensional buffer is aircraft referenced in x and y and an altitude dimension is referenced to altitude above the earth and the first component translates the radar return data into the coordinate system of the three-dimensional buffer.
In accordance with still another aspect of the invention, the first component stores return data based on actual radar tracking or antenna pointing.
As will be readily appreciated from the foregoing summary, the invention provides an improved weather radar display system.